The Health Services Union will hold a family picnic day in Warrawong on Sunday to rally community support to save Port Kembla Hospital's food production unit and the jobs of 34 staff.
The union has already collected more than 5000 signatures on a petition protesting a plan by HealthShare NSW to transfer food production for the region's hospitals to Sydney's Royal Prince Alfred Hospital later this year.
HSU regional organiser Graham Conroy said members hoped to get closer to their goal of 10,000 signatures at the picnic day, which would prompt the matter to be debated in Parliament.
"We are very grateful to the people of the Illawarra who have already signed our petition and supported the staff at Port Kembla," Mr Conroy said.
"The jobs of 34 staff would be directly affected if the food production moves to Sydney, although it will have a roll-on effect for the suppliers.
"And we know from our campaigning, that the people of the Illawarra are not happy that hospitals throughout the region will be exchanging fresh meals for frozen, pre-packaged stuff."
Mr Conroy said the union remained in negotiations with HealthShare NSW, which flagged earlier this year that it was planning to move food production to Sydney due to the introduction of a new menu.
A HealthShare spokeswoman said the Port Kembla unit was not able to implement that menu without a major upgrade.
Mr Conroy said the HSU was calling on the state government to find funds for that upgrade, rather than close the facility and put off workers.
The family picnic day will be held at Kully Bay Park, Northcliffe Drive, Warrawong, on Sunday from 10am to 2.30pm with activities and a gold coin donation barbecue for Wollongong Hospital's renal oncology unit.